test: add --stat:insn to linear trace tests

The tests test/src/linear-tip.ptt and test/src/linear-fup-tip_pgd.ptt use
ptxed's --stat option to avoid having to specify a rather big number of
addresses for the expected output.

Add --stat:insn to not break the test when we add more statistics.

Change-Id: I8d428ecb42f81cac98cfcb3052a4d7cb9c2e2cf6
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>